In some cases the roles are reversed, which clouds the issue of redress. (religion-online.org)
You can take an old, sealed bottle and compare it to today's equivalent bottling, but there can have been various subtle changes in the production process over the years, such as cask selection, which cloud the issue and you may not be comparing like for like. (thedrinksreport.com)
Summers clouds the issue further by separating minorities into two groups, people of color and women. (sciencemag.org)